Sound-amplifying device for telephone receivers



. Jan. 8, 1929; X 1,698,583

F. J. EMP SON SOUND AMPLIFYING DEVIGE FOR .TELEBHONE RECEIVERS Filed April 4, 1927 awn/7m 77/1! dazz- Patented Jas. s, 1929.

UNITED, STATES- rannnnrcx ma ns nnrson, or-nonmennna, ITALY.

, SOUND-AMPLIFYING DEVICE FOR TELEPHONE RECEIVERS.

Application filed April 4, 1927, Serial No. 18 0,8 81, and in Great Britain April 24, 1928.

This invention relates to sound amplifying devices for telephone receivers of the kindwherein there are two or more resonating shells arranged one wlthin the other in such 5 a manner as to leave annular spaces between them, for example, as described in the specification of my British Letters Patent No. 216,912. The improved device may be advantageously employed in the radio transmission of speech, and of vocal and instrumental music. 7

According to my invention, I provide two opposite sides of the outermost shell of the nest or series of resonating chambers or shells with seats or sockets to receive the ear pieces of a pair of headphones of any suitable known type, such-seats or sockets having apertures therein which communicate withtubes that extend transversely through the corresponding side walls of the resonating shells and extend into the interior space of the innermost shell, where they are bent or shaped, e. g. flared, so as todirect the sound waves issuing therefrom towards tlgpinner end of 'the innermost resonating c ber. At the inner end of the nest there is arifiged a sound deflector or reflector which is preferably of-parabolic form in section, so that thesound waves issuing from the tubes above be arranged to form the innerend'of either '35 a middle or the outermost shell, the resonating shell or shells lying within the one bear--" ing the reflector being provided with open inner ends. I

By this means, e. g. when the radio receiving set has been tuned to receive the desired waves, the head phones can be removed from the ears of the person making the adjustment and then sprung on to the'seats or sockets on the outside of the resonator. The whole combination of head phonesand resonator then forms a loud speaker.

In order further to increasethe volume of sound issuing from the resonating apparatus, or as an alternative to the lateral tubes for 0 receiving the sound' waves from a pair of mentioned are directed towards such reflector nating shells or chambers, for example, these last mentioned tubes may be arranged in a line that is substantially. perpendicular to the line joining the axes of the'tubes through In some casesthe tubes extending into the interior space of the compound resonator may be united in a common bell-mouth or trumpet which is directed inwardly in order to conduct the sound waves to'the sound deflectoror reflector-at the'inner end of the resonator.

In the accompanying drawing which illustrates a form of the amplifying device according to this invention.

Figure 1 is a perspective view of the amplifying device.

Figure 2 is a plan view showing a pair of headphones fitted" upon the amplifying deviceyand g Figure 3 is a section on the line III-III of Figure 2:

Figure 4 is a horizontal section showing a I device comprises a series of three nested resonating shells or chambers A, B, O and upon two opposite sides of the outermost shell- A there are arranged seats or sockets D to receive theearpieces-E of}?1 Lair of head- 7 "w 'c are adapt 33 phones of any suita le ed to be sprung on to seats D and to be retained in position .by the spring head band F of the headphones. The spaces within the nested shells may be put into communication .with each other through holes formed in such shells. Holes may also be formed in the outermost shell as shown in Figure 2.

The seats orsockets'D have apertures G therein which communicate withtubes H that extend transversely through the corresponding side walls of the resonating shells, B, G

into the'interior space of the innermost shell C where the ends of the tubes H are shaped,

e. g. flared, so as'to direct the sound waves issuing therefrom towards the inner end of the innermost resonating shell or chamber.

' At the inner end of the nest of resonating wards the open outer ends of the resonating shells forming the resonator or sound amplifying device andare caused to issue from such open ends of the resonator in theform of substantially parallel beams. The reflector or deflector J may be arranged at the inner end of the outermost shell or of an intermediate shell in order to close the inner end of said shell. The resonating shell or shells lying within the one upon which the sound deflector or reflector J is arranged have their inner ends open. i

By this means, the radio receiving set may be tuned to receive the desired waves by a person using a pair of headphones in the usual manner, and when the receiving set has been satisfactorily tuned, the ear pieces E of the headphones maybe sprung on to the seats or sockets D on the outside of the resonator A and retained in position thereon by the elastic head band F of the headphones. The whole combination of head phones and resonator then forms a loud speaker.

If desired, the multiple resonator can be combined or used separately with a stationary diaphragm or like telephone receiver,

' such as those used in the baseof an ordinary loud speaker. In this case, an additional transverse tube K is provided for connection with such telephone receiver or a pair of such tubes may be provided as shown, to receive two telephone receivers having difierent acoustic and electrical constants, thereby enabling a wider range of sounds tobe effieiently reproduced. These receivers can be detachably connected to the tubes K, K by means of india rubber sleeves or in any other suitable manner.

The sound conducting tubes H and K may be formed either entirely of metal or partly of metal and wood or partly-of soft indiarubber.

The tubes are preferably turned through a right angle or thereabouts at their inner ends as shown, so as to direct the sound waves towards the deflector orreflector J.

In the arrangement shown in Figure 4, the tubes H, K are united in a common bellmouth orifice M directed towards the reflecting surface J.

In cases where the shellsof the resonator are made alternately of wood and metal, the tubes H, K, H, K, or the metal parts of such tubes, may advanageously be secured to a metal shell the free portions of the tubes being arranged to extend through clearing holes in the wooden shell or shells, or they may be each secured by a flange to the outermost shell as shown.

I claim:

1. A sound amplifying device for radio and through the walls of .flector of parabolic form at and having their inner ends directed towards the inner ends ofthe shells, and a sound defleet or at the inner end of said resonator.

3. A sound amplifying device according to claim 2 comprising seatings for telephone receivers communicating with the outer ends of the sound conducting tubes.

4. A telephone amplifying device for radio and like telephone receivers, comprising a plurality of tubular shells arranged one within another and; spaced apart to form'a' resonator, sound conducting tubes extending through the walls of the shells to the interior of the inner shell, a bell-mouthed trumpet directed towards the inner end of the shells and connected to the inner ends of the tubes, seatings for telephone receivers in communication with the outer ends of said tubes, and

the walls of said a sound deflector at the inner end of said resonator.

5. A sound amplifying device according to claim 4 wherein the sound deflector at the inner end-of the resonator is of parabolic form.

.6. A telephone amplifying device for radio and like telephone receivers comprising a plurality of tubular shells arranged one within another and composed alternately of wood and metal, sound conducting tubes extending said shells, a bell mouth trumpet in the interior of the inner shell directed towards the inner ends of said shells .and connected to the inner ends of said tubes, seatings for telephone recelvers 1n communication with the outer ends of said tubes, and a sounddeflector of parabolic form at the 111- ner ends of said shells.

7. A telephone amplifying device for radio and like telephone receivers compr sing a plurality of tubular shells arranged one within another and composed alternately of wood and metal, sound conducting tubes extending through the walls of said. shells and secured to a metal interior of the inner shell directed towards the inner ends of said shells and connected to the inner ends of said tubes, seatings for telephone receivers in communication with shell, a hell mouth trumpet in thethe outer ends of said tubes, and a sound de-- the inner ends of said shells.

8. A telephone amplifying device for radio negates 3 and like tele hone receivers comprising a the inner ends of said shells and "connected plurality of tu ular shells arranged one withto the inner ends of saidtubes, seatings for in another and composed alternately of wood telephone receivers in communication with 10 and metal, soundconducting tubes extending the outer ends of said tubes, and a sound de- 5 through the walls of said shells and secured flector at the inner endsof said shells formed to a metal shell, :1 bell mouth trumpet in the integrally with a shell. l 7 interior of the inner shell directed towards FREDERICK JAMES EMPSON. i 

